:The Prime Meridian we use today (zero degrees longitude), was not formally established at the Royal Observatory in Greenwich, England until 1884. For a long time, the location of zero longitude varied from country to country and sometimes even from one mapmaker to the next. Many early North Carolina Maps show two different longitudes, one at the top of the map, and one at the bottom. In the United States, mapmakers frequently measured longitude from Washington, D.C. or from Philadelphia, while French mapmakers measured longitude from Paris. While this can be confusing, mapmakers were usually careful to note where they were measuring from (for example, "Longitude west from London."). However, because this was not always specificed, modern viewers of historic maps who are relying on a Longitude measurement for comparison with current maps should keep in mind that an older map that appears to be "off" may simply be measuring longitude from a different location.

Revision as of 12:01, 29 August 2008

Contents

Contours or Contour Lines

do.

Abbreviation for "ditto." This is often used in map legends to save space.

English Statute Miles

"The international mile (and before 1959, the statute mile) is the distance typically meant when the word mile is used without other qualifying words (e.g. nautical mile, see below). The international and statute miles are both equal to 5,280 feet, but the international mile is defined in terms of the international foot (0.3048 m), while the statute miles of the various English-speaking countries were based on the national foot of each country. The (mostly obsolete) U.S. statute mile is based on the U.S. survey foot (which is exactly 1200/3937 m) and differs from the international mile by about 3 mm. [7]

The name statute mile originates from a Statute of the Parliament of England in 1592 during the reign of Elizabeth I. This defined the statute mile as 5,280 ft or 1,760 yards; or 63,360 inches. Both statute and international miles are divided into eight furlongs (the length generally that a furrow was ploughed before the horses were turned, furlong = furrow-long). In turn a furlong is ten chains (a surveyor's chain, used as such until laser range finders took over); a chain is 22 yards and a yard is three feet, making up 5,280 ft." - http://en.wikipedia.org/wiki/Mile

Hachures

Longitude West from . . .

The Prime Meridian we use today (zero degrees longitude), was not formally established at the Royal Observatory in Greenwich, England until 1884. For a long time, the location of zero longitude varied from country to country and sometimes even from one mapmaker to the next. Many early North Carolina Maps show two different longitudes, one at the top of the map, and one at the bottom. In the United States, mapmakers frequently measured longitude from Washington, D.C. or from Philadelphia, while French mapmakers measured longitude from Paris. While this can be confusing, mapmakers were usually careful to note where they were measuring from (for example, "Longitude west from London."). However, because this was not always specificed, modern viewers of historic maps who are relying on a Longitude measurement for comparison with current maps should keep in mind that an older map that appears to be "off" may simply be measuring longitude from a different location.

Projection

Rhumblines

also rhumb lines or rumb lines, or loxodrome. "This line of constant bearing is called a Rhumb line. The word 'rhumb' (or sometimes rumb and it is the same in French though not very well known) comes from the name of angle measurement representing the 'point' on the old fashioned compass cards. There are 32 'rhumbs' in 360 degrees, hence a rhumb is 11 1/4 degrees." (Source: http://jacq.istos.com.au/sundry/navrhumb.html)

Detail from "A new chart of the coast of North America from Cuurituck Inlet to Savannah River...," 1794. NCC call number Cm912m N87 1794.

Detail from "A new chart of the coast of North America from Cuurituck Inlet to Savannah River...," 1794. NCC call number Cm912m N87 1794.

Sculp. (also Sc., Sculpt., or Sculpsit)

Variations of this term (from the Latin word sculpsit, meaning to carve or engrave) are used to denote the name of the engraver of the map. The name of the engraver is often listed at the bottom of the map.